Payment protocol doc was removed by afk11

DaShak · afk11 · commit 1cb0d047cf7c · 2018-07-31T10:38:22.000+01:00
Redundant; superseded by Transaction.md
diff --git a/doc/Introduction.md b/doc/Introduction.md
@@ -6,8 +6,6 @@
 
 [Transaction](Transaction.md)
 
-[Payment Protocol](Payment%20Protocol.md)
-
 [Serialization](Serialization.md)
 
 [Types](Types.md)
